Engine rattle on cold start

[poortomsacold]

Bingo!
Vanos. It means that when you get an overhaul kit for it you need to get one that includes the rattle rings.
It does mean that you can relax a little though as apart from losing a bit of torque (which was probably gone long before you got it) there is no immediate rush to save your engine.

https://x8r.co.uk/for-bmw-double-twin-d ... skets.html

Exactly as you suspected! Thanks again for all of your help so far. This forum is brilliant!

[enuff_zed]

Bingo!
Vanos. It means that when you get an overhaul kit for it you need to get one that includes the rattle rings.
It does mean that you can relax a little though as apart from losing a bit of torque (which was probably gone long before you got it) there is no immediate rush to save your engine.

https://x8r.co.uk/for-bmw-double-twin-d ... skets.html

Exactly as you suspected! Thanks again for all of your help so far. This forum is brilliant!

To be fair, it wasn't just me though.

[poortomsacold]

Bingo!
Vanos. It means that when you get an overhaul kit for it you need to get one that includes the rattle rings.
It does mean that you can relax a little though as apart from losing a bit of torque (which was probably gone long before you got it) there is no immediate rush to save your engine.

https://x8r.co.uk/for-bmw-double-twin-d ... skets.html

Exactly as you suspected! Thanks again for all of your help so far. This forum is brilliant!

To be fair, it wasn't just me though.

No there are some extremely knowledgeable folks on this forum. Am hoping that once the seals are changed the rare hesitation I have will go. Then at some stage to look into the clunk I sometimes get from the rear end when I change gears without compensating sufficiently well with the accelerator - another issue that seems quite common....it never ends!

[enuff_zed]

The whole point of the vanos system is to adjust the angle between the cams, using oil pressure, directed by solenoids and shuttle valves, to ensure the optimum timing at all engine speeds.
When the seals fail the oil sneaks past instead of acting to adjust the cam timing.
I have a 3.0i that I am (very) slowly doing up. When I connect my Autophix 5900 code reader to it I can see real time feedback on several systems, including the cam angles. At the moment, whatever engine speed I try, the angles stay exactly the same. So I know this one needs the vanos seals sorted to. Luckily it is quiet though, so I may get away with the cheaper kit.
If it encourages you at all, 3 years go I bought my wife an E85 2.5i Auto as a Valentine's present. Prior to that I had no knowledge of these cars at all. So it will come to you. Every job you do will add to your knowledge.

[patriot66]

Exactly as you suspected! Thanks again for all of your help so far. This forum is brilliant!

To be fair, it wasn't just me though.

No there are some extremely knowledgeable folks on this forum. Am hoping that once the seals are changed the rare hesitation I have will go. Then at some stage to look into the clunk I sometimes get from the rear end when I change gears without compensating sufficiently well with the accelerator - another issue that seems quite common....it never ends!

It does end...eventually Twenty year old cars. Once you replace/repair all the original components that can give problems due to age/decomposition/heat cycles etc then life becomes much easier.
By the way that clunk from the rear end driveline will more than likely be the prop-shaft splines into the diff requiring some grease Drop the exhaust, drop the prop-shaft, apply correct grease...sorted. Another job you can tick off the list

[poortomsacold]

To be fair, it wasn't just me though.

No there are some extremely knowledgeable folks on this forum. Am hoping that once the seals are changed the rare hesitation I have will go. Then at some stage to look into the clunk I sometimes get from the rear end when I change gears without compensating sufficiently well with the accelerator - another issue that seems quite common....it never ends!

It does end...eventually Twenty year old cars. Once you replace/repair all the original components that can give problems due to age/decomposition/heat cycles etc then life becomes much easier.
By the way that clunk from the rear end driveline will more than likely be the prop-shaft splines into the diff requiring some grease Drop the exhaust, drop the prop-shaft, apply correct grease...sorted. Another job you can tick off the list

That’s very handy to know - will add that to the to do list! I’ll get there in the end I’m sure!

[poortomsacold]

The whole point of the vanos system is to adjust the angle between the cams, using oil pressure, directed by solenoids and shuttle valves, to ensure the optimum timing at all engine speeds.
When the seals fail the oil sneaks past instead of acting to adjust the cam timing.
I have a 3.0i that I am (very) slowly doing up. When I connect my Autophix 5900 code reader to it I can see real time feedback on several systems, including the cam angles. At the moment, whatever engine speed I try, the angles stay exactly the same. So I know this one needs the vanos seals sorted to. Luckily it is quiet though, so I may get away with the cheaper kit.
If it encourages you at all, 3 years go I bought my wife an E85 2.5i Auto as a Valentine's present. Prior to that I had no knowledge of these cars at all. So it will come to you. Every job you do will add to your knowledge.

That’s reassuring. A few weeks ago I’d not really done any work on a car, so have done more than ever before. Don’t think I’d ever heard of a vanos or disa valve but today took the latter out to inspect it - never thought I’d tinker with parts of the engine of a Z4 I must say. It’s good to learn!

[poortomsacold]

So after just over a week of noticing the rattle it has gotten somewhat worse - it sounded pretty noisy when starting the car today. When the temperature was up to normal the rattle cannot really be heard when in neutral/idle, but can be heard when accelerating. Does this all sound pretty standard for a vanos that needs a rebuild? Is there any risk in keeping driving it?

Thanks!

[enuff_zed]

So after just over a week of noticing the rattle it has gotten somewhat worse - it sounded pretty noisy when starting the car today. When the temperature was up to normal the rattle cannot really be heard when in neutral/idle, but can be heard when accelerating. Does this all sound pretty standard for a vanos that needs a rebuild? Is there any risk in keeping driving it?

Thanks!

If it’s getting worse then I’d move it up the list a bit. I know you’re focused on the bodywork but that can hang on. The engine needs looking after.

[poortomsacold]

So after just over a week of noticing the rattle it has gotten somewhat worse - it sounded pretty noisy when starting the car today. When the temperature was up to normal the rattle cannot really be heard when in neutral/idle, but can be heard when accelerating. Does this all sound pretty standard for a vanos that needs a rebuild? Is there any risk in keeping driving it?

Thanks!

If it’s getting worse then I’d move it up the list a bit. I know you’re focused on the bodywork but that can hang on. The engine needs looking after.

Totally agree - will try to get this sorted shortly so that the good bodywork will then be on a working car...! Does the vanos often deteriorate quite quickly once a rattle becomes noticeable do you know?

[enuff_zed]

So after just over a week of noticing the rattle it has gotten somewhat worse - it sounded pretty noisy when starting the car today. When the temperature was up to normal the rattle cannot really be heard when in neutral/idle, but can be heard when accelerating. Does this all sound pretty standard for a vanos that needs a rebuild? Is there any risk in keeping driving it?

Thanks!

If it’s getting worse then I’d move it up the list a bit. I know you’re focused on the bodywork but that can hang on. The engine needs looking after.

Totally agree - will try to get this sorted shortly so that the good bodywork will then be on a working car...! Does the vanos often deteriorate quite quickly once a rattle becomes noticeable do you know?

I have not had one that actually got as far as rattling yet.
What would concern me is whether any bits can break away and get into the oil?
bigwinn, do you have more experience of this issue?

[poortomsacold]

Well I’ve elected for the better safe than sorry solution - booked her in with my local mechanic on Monday so he can diagnose the problem and we can take it from there!

[bigwinn]

The vanos rattle as far as I understand is not critical

It’s wear on the bearing rings which move in the unit- so ultimately it could fail but I’ve never seen that amount of wear

[poortomsacold]

The vanos rattle as far as I understand is not critical

It’s wear on the bearing rings which move in the unit- so ultimately it could fail but I’ve never seen that amount of wear

Thanks for that. Will report back once I know exactly what the issue is.

[poortomsacold]

To be fair, it wasn't just me though.

No there are some extremely knowledgeable folks on this forum. Am hoping that once the seals are changed the rare hesitation I have will go. Then at some stage to look into the clunk I sometimes get from the rear end when I change gears without compensating sufficiently well with the accelerator - another issue that seems quite common....it never ends!

It does end...eventually Twenty year old cars. Once you replace/repair all the original components that can give problems due to age/decomposition/heat cycles etc then life becomes much easier.
By the way that clunk from the rear end driveline will more than likely be the prop-shaft splines into the diff requiring some grease Drop the exhaust, drop the prop-shaft, apply correct grease...sorted. Another job you can tick off the list

Amy idea how long it'd take a mechanic to drop the prop shaft and apply the correct grease? I'm taking it to my mechanic next week for the rattle and whilst there will get the gearbox and diff oil changed, so wasn't sure if this was another job to get done at the same time perhaps?